1. Field of the Invention
The present invention relates to a display device having a pixel array in which pixel circuits are arranged in a matrix and a display driving method thereof, and particularly to a display device employing e.g. an organic electro-luminescence element (organic EL element) as its light emitting element.
2. Description of the Related Art
For example, as disclosed in Japanese Patent Laid-Open No. 2003-255856 and Japanese Patent Laid-Open No. 2003-271095, image display devices employing an organic EL element for the pixels have been developed. The organic EL element is a self-luminous element and therefore has the following advantages over e.g. a liquid crystal display device: higher image visibility, no necessity for a backlight, higher response speed, etc. Furthermore, the luminance level (grayscale) of each light emitting element can be controlled based on the value of the current flowing through the light emitting element (so-called current-control type).
As the driving system of the organic EL display, a simple-matrix system and an active-matrix system are known, similarly to the liquid crystal display. The simple-matrix system has problems of e.g. difficulty in realization of a large-scale, high-definition display although having a simple configuration. Therefore, presently development of the active-matrix system is being actively promoted. In this system, the current flowing to the light emitting element inside each pixel circuit is controlled by active elements (generally thin film transistor (TFT)) provided inside the pixel circuit.